Development of a Megasonic System for Cleaning Flat Panel Display

Abstract

When fabricating flat panel displays (FPDs), cleaning process is important in the preparation of next steps. A megasonic system for cleaning FPD which can remove smaller particles with lower power and lower consumptions of chemical and UPW was designed and manufactured. The anti-resonance frequency of the lead zirconate titanate (PZT) actuator was measured, and the value was 992 kHz. The impedance graph of the cleaning system was analyzed using commercial finite element method (FEM) analysis software Ansys, and the obtained value was 992 kHz. This agreed well with the measured value of 989 kHz. The performance of the developed system was evaluated by comparing the acoustic pressures with the conventional product. As a result, the acoustic pressures of the developed system were three times larger than that of the commercial system (conventional type: 13.9 kPa, the developed one: 43.1 kPa). In addtion, the PRE test was performed and the 83% particles were removed using 64% reduced power and 80% reduced chemical consumptions.